Prior art of possible relevance includes the following U.S. Pat. Nos. Martin 3,160,771; Vieilleribiere 3,927,338; Andersson 3,470,405; Maiese 4,224,663; Scharli 3,366,171; and Geddry 3,474,358.
Current, voltage and frequency limitations of switch assemblies formed of arrays of semiconductors are determined by the assembly's ability to maintain the operation of each individual semiconductor within its operating envelope. For example, where plural semiconductors are arranged in electrical parallel to operate as a switch, under high power loading, if the semiconductors are not turned on or off simultaneously, one or more of the semiconductors in the assembly may be momentarily, temporarily overloaded with the consequence that it may be damaged or fail during such momentary overload. This in turn will reduce the capacity of the assembly, possibly causing total failure the next time high loading is encountered due to such reduced capacity.
Another difficulty that may be encountered is stored energy in the system. When the semiconductors are turned off, such stored energy may be converted into a ringing signal which is damped oscillating high voltage spikes. Ultimately, the ringing signal converts to heat which can limit switch capacity, again giving rise to potential failure.
The present invention is directed to overcoming one or more of the above problems.